Air-heating- furnace



2 2 Sheets-Sheet I.

E. D. NORCROSS.

Hot-Air Furna ce.

Patented" Feb. 24, 1852.

2 Sheets-Sheet 2, D. NORCROSS.

} Hot-Air Furnace.

N0. 8,758. Patented Feb. 24 1852.

UNITED STATES PATENT OFFICE.

n. D. NoRoRoss, or AUGUSTA, MAINE.

Ara-HEATING FURNACE.

Specification of Letters Patent No. 8,758, dated February 24, 1852.

To all whom it may concern: M

Be it known that I, EDMUND D. Nononoss, of Augusta, in the county ofKennebec and State of Maine, have invented a new and useful Hot-AirFurnace for Heating Buildings, &c., and that the following is a full,clear, andexact description of the principle or character whichdistinguishes it from all other things before known and of the usualmanner of making, modifying, and using the same.

The nature of my invention consists in the construction and attachmentof the door frame, the constructive arrangement of the fire plate, andthe construction of the furnace, to adapt it thereto, and the mode ofadmitting the cold airto be heated, in combination with the peculiarmanner of caus- .ing the products of combustion, heat, &c.,

to be revolved, so as to obtain the greatest amount of heat in a cheap,durable, and

simple manner. t

Figure 1 1s a perspectlve View of the furnace set up preparatory tobeing inclosed in the brick Walls. Fig. 2 is a perspective view of thedoor frame of the furnace. Fig. 3 aremovable fire-plates which come incontact with the fuel, and protect the sides. of the furnace from injuryby heat. Fig. t is a view of the rearplate of the furnace, showing aportion of the brickwork. Fig. 6 is a vertical longitudinal sec tion ofthe furnace. Fig. 7 is asection of the surrounding brick work, in thesame plane as Fig. 6. Fig. 8 is a ground plan of the brick workofthefurnace.

The construction is as follows: The cross section of the furnace isovate, the smaller end being downward. The advantages of this formare,first, contracting the furnace at the point where the fuel lies, andenlarging at the same time the body of the furnace where the air isheated, and the gases are revolved prior to their exit. Secondly, thefacility which it gives, by means of its inclined sides, for the removalof the fire plates (to be hereafter described) and retaining the regularcurved figure, as shown in the drawings.

The longitudinal section of this portion of plate has a projectingflanch (D) perpendicular to its surface, extending backward the breadthof eight inches, more or less,

(See Fig. 1 A.) The back and of similar outline to a cross section ofthe furnace without the bottom. There are circular apertures (B) in thefront and back plates, with pipes extending from one to the other (seeFig. 6) and opening to the spaces, front and back of the furnace. Theair is supplied from the exterior atmosphere through the brick wallbelow, and passes up into the pipes above named through the air chamberformed by the flanch D. The smoke pipe (0) opens from the front plateover the fire door, and may extend up and back over the furnace, asshown in Fig. l, or in any other convenient way; the opening into whichthe door frame is fixed in the front plate is somewhat higher than theframe itself; and upon the upper and lower side of the door frame arefianches (e), which, when the door frame is put in place, hook on to thefront plate, above and below. The upper fianchshould be about double thedepth of the lower ones. It is first inserted, and the frame pressedupward till the lower one enters, when it is pressed down to its place,and remains firmly affixed in its place.

The fire plates above named, shown in Fig. 3, are constructed andapplied as fol lows: I place in the bottom of the body of the furnace,inside, two curved bars (00), which I denominate dogs. These fit thecurvature of the bottom, and extend some distance up the sides. They arerecessed at either end on their outsides, so as to leave a space betweenthem and the side of the furnace sufiicient to slip in three or moreplates (y) on each side, to form a lining to protect the furnace whichcan be removed without disturbing the other parts. On these plates aresmall projections (a), which pass down on each side of the dogs, tosteady them, and hold them in place. The furnace is elevated andsupported on four legs, and the parts are held together by rods (w)passing from the front to the back plate. The brick work is. built up soas to form a chamber around the furnace, as in other structures ofthiskind, that portion of this air chamber, at the back, being dividedfrom the rest, above the bottom, by the flanch D above described. Theair for combustion enters the fire-door, and causes a circulation of theheated gases within, by

first driving them backward and upward, circulating around the air tubesabove, whence they pass forward and make then exit through the smokepipe in front. This is very important, especially Where air pipes arethus used, as it causes the most perfect diffusion and extraction of theheat, Which would not be the case if the smoke pipe opened through theback plate into the furnace.

Having thus fully described my improvement, What I clalm therein, andfor Which I desire to secure Letters Patent, is

1. Arranging the fire plates, in the manner set forth, so as to renderthem movable, in combination With the inclined sides of the furnace.

2. I also claim the combination of the air pipes passing through thefurnace With the rear fianch D; and With the arrangement for revolvingthe gases Within the furnace backward and upward, thence passing themolf in front, as described, the cold air being brought to the outside ofthat part of the furnace and tubes, against Which the heat firstimpinges, thus protecting it, and rendering the parts more durable, andmore equally distributing the heat.

EDMUND n. NoRcRo ss.

Witnesses BECKWITH WEST, I. A. SMITH.

